#include "flutter_window.h"

#include <optional>

#include "flutter/generated_plugin_registrant.h"

FlutterWindow::FlutterWindow(const flutter::DartProject& project) : project_(project) {}

FlutterWindow::~FlutterWindow() {}

bool FlutterWindow::OnCreate() {
    if (!Win32Window::OnCreate()) {
        return false;
    }

    RECT frame = GetClientArea();

    // The size here must match the window dimensions to avoid unnecessary surface
    // creation / destruction in the startup path.
    flutter_controller_ =
        std::make_unique<flutter::FlutterViewController>(frame.right - frame.left, frame.bottom - frame.top, project_);
    // Ensure that basic setup of the controller was successful.
    if (!flutter_controller_->engine() || !flutter_controller_->view()) {
        return false;
    }
    RegisterPlugins(flutter_controller_->engine());
    SetChildContent(flutter_controller_->view()->GetNativeWindow());

    flutter_controller_->engine()->SetNextFrameCallback([&]() { this->Show(); });

    // Flutter can complete the first frame before the "show window" callback is
    // registered. The following call ensures a frame is pending to ensure the
    // window is shown. It is a no-op if the first frame hasn't completed yet.
    flutter_controller_->ForceRedraw();

    return true;
}

void FlutterWindow::OnDestroy() {
    if (flutter_controller_) {
        flutter_controller_ = nullptr;
    }

    Win32Window::OnDestroy();
}

LRESULT
FlutterWindow::MessageHandler(HWND hwnd, UINT const message, WPARAM const wparam, LPARAM const lparam) noexcept {
    // Give Flutter, including plugins, an opportunity to handle window messages.
    if (flutter_controller_) {
        std::optional<LRESULT> result = flutter_controller_->HandleTopLevelWindowProc(hwnd, message, wparam, lparam);
        if (result) {
            return *result;
        }
    }

    switch (message) {
        case WM_FONTCHANGE:
            flutter_controller_->engine()->ReloadSystemFonts();
            break;
    }

    return Win32Window::MessageHandler(hwnd, message, wparam, lparam);
}
